Heating a short section of tape or wire to a controlled temperature

ABSTRACT

Systems and methods of heating a conductive ribbon for sample collection and/or sample processing comprises coupling conducting pads to the conductive ribbon, applying a signal across the conducting pads to cause the conductive ribbon to heat up, taking a measurement of at least one electrical property associated with the conductive ribbon in response to the applied signal, computing a correction for the applied signal to achieve a desired temperature suitable for fixing a sample to the heated conductive ribbon, and adjusting the applied signal to regulate the heat of the conductive ribbon to the desired temperature for a predetermined time.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/US2011/050825, filed Sep. 8, 2011, entitled “HEATING A SHORT SECTIONOF TAPE OR WIRE TO A CONTROLLED TEMPERATURE”, which claims the benefitof U.S. Provisional Patent Application Ser. No. 61/381,204, filed Sep.9, 2010, entitled “HEATING A SHORT SECTION OF TAPE OR WIRE TO ACONTROLLED TEMPERATURE”, the disclosures of which are herebyincorporated by reference.

BACKGROUND

The present invention relates to metallic and metallic-coated conductiveribbons, and in particular, to systems and methods for heating a shortsection of such metallic or metallic-coated conductive ribbons.

The monitoring of particulate matter has received an increasing amountof attention in recent years because of the potential impact ofparticulates on radiative and climatic processes, on contamination ofproducts, on human health and the role particles play in atmospherictransport and deposition of pollutants. As an illustration, it may bedesirable to detect the presence of particulates found in the air, inwater supplies or on persons. It may also be desirable to detect thepresence of particulates on materials that may be found in semiconductorclean rooms, pharmaceutical production facilities and biotechnologylaboratories to verify that there has been no contamination produced insuch environments that would create undesirable environmental exposuresor adversely affect manufacturing, testing or experimental processes.

As another illustration, it may be desirable to analyze the air in apredetermined location for particulates that fall within a range ofsizes that can be inhaled, such as naturally occurring or artificiallyproduced airborne pathogens, allergens, bacteria, viruses, fungi andbiological or chemical agents that are found in or are otherwiseintroduced into the location. For example, the ability to detect thepresence of particular airborne particulates in hospitals, nursinghomes, rehabilitation centers and other care facilities may bebeneficial to assist in preventing the spread of disease, infection orharmful bacteria.

The monitoring of particulate matter further finds application forassessments of human health risk, environmental contamination and forcompliance with National Ambient Air Quality Standards (NAAQS), e.g., tomonitor the air in public and commercial building air clean-up anddistribution systems, work sites such as mines, sewage facilities,agricultural and manufacturing facilities, outside areas such as streetcorners, flues and smokestacks and other locations where it is desirableto monitor environmental hygiene.

BRIEF SUMMARY

According to various aspects of the present invention, ribbons areutilized in the collection and storage of samples for the monitoring ofparticulate matter. More particularly, a sample may be collected onto aribbon, such as a conductive ribbon or a ribbon with a thin metalliccoating. Further, a collected sample may be processed while the sampleis contained on the conductive ribbon. In this regard, it may benecessary to heat a short section of the conductive ribbon to acontrolled temperature.

According to further aspects of the present invention, a system forheating a ribbon comprises a non-conductive base, a surface forreceiving the conductive ribbon, and a pair of conducting pads, each padarranged to contact a conductive portion of the conductive ribbonpositioned on the non-conductive base. A variable power supply forms acircuit with the pair of conducting pads and the conductive ribbon. Thesystem also comprises a sensor to measure at least one electricalcharacteristic of the circuit and a controller coupled to the variablepower supply.

The controller controls the variable power supply to apply a signal tothe conductive ribbon and a measurement is taken using the sensor inresponse to the applied signal. The controller computes a correction forthe applied signal to achieve a desired temperature suitable forprocessing a sample on the heated conductive ribbon and adjusts theapplied signal to regulate the heat of the conductive ribbon to thedesired temperature. In this regard, the controller holds the conductiveribbon at the desired temperature for a time that is suitable forprocessing a sample on the conductive ribbon.

According to further aspects of the present invention, a method ofheating a conductive ribbon comprises coupling conducting pads to theconductive ribbon, applying a signal across the conducting pads to causethe conductive ribbon to heat up, taking a measurement of at least oneelectrical property associated with the conductive ribbon in response tothe applied signal, computing (based on the measurement) a correctionfor the applied signal to achieve a desired temperature suitable forprocessing a sample on the heated conductive ribbon and adjusting theapplied signal to regulate the heat of the conductive ribbon to thedesired temperature. In this regard, the conductive ribbon is held atthe desired temperature for a time that is suitable for processing asample on the conductive ribbon.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a flow chart illustrating a method of heating a conductiveribbon for sample collection or processing according to various aspectsof the present invention;

FIG. 2 is a schematic illustration of a system for heating a conductiveribbon for sample collection or processing according to various aspectsof the present invention; and

FIG. 3 is a controller for the system of FIG. 2, according to variousaspects of the present invention.

DETAILED DESCRIPTION

Currently, biological samples that have been collected, e.g., by aerosolsamplers, biological culture and reagent samples, infectious samplesfrom patients and other mixed samples, often contain impurities thatimpede an associated analytical process. As such, post collectionprocessing of a sample may be performed to prepare the sample for theappropriate analysis. According to various aspects of the presentinvention, systems and methods are provided to heat a selected shortsection of a conductive ribbon. The heated ribbon may be utilized, forexample, for processing a sample collected onto, or otherwisetransferred to, the conductive ribbon, e.g., for fixing or drying asample containing proteins or micro-organisms.

Referring now to the drawings, and in particular to FIG. 1, a method 100of heating a conductive ribbon is illustrated. The method 100 may beutilized for processing a sample, e.g., to fix a sample to theconductive ribbon and/or to dry a washed, incubated sample on theconductive ribbon, etc.

The method 100 comprises coupling conducting pads to a conductive ribbonat 102, applying a signal across the conducting pads to cause theconductive ribbon to heat up at 104 and taking a measurement associatedwith the conductive ribbon in response to the applied signal at 106. Themethod 100 further comprises computing a correction for the appliedsignal to achieve a desired temperature suitable for processing a sampleon the heated conductive ribbon at 108 and adjusting the applied signalto regulate the heat of the conductive ribbon to the desired temperatureor temperature range at 110. The method 100 further comprises holdingthe conductive ribbon at the desired temperature (or within a desiredtemperature range) for a selected time, e.g., a time that is suitablefor processing a sample on the conductive ribbon at 112.

To maintain the desired temperature or temperature range, the method 100loops back to 106 to take a new measurement of associated with theconductive ribbon, to compute a new correction and adjust the signal.Adjustments can be performed continuously, periodically, discretely orotherwise, to update the value of the signal applied to the conductiveribbon so as to maintain a desired temperature or acceptable temperaturerange. In this manner, the temperature of the conductive ribbon iscontrolled to a repeatable, desired temperature for sample collection orprocessing.

In an illustrative example, two spaced apart pads clamp to the ribbon at102. Applying a signal at 104 comprises applying a low voltage to theconductive ribbon through the conducting pads using a suitable voltagesource. Correspondingly, taking a measurement at 106 comprises sensing acurrent in the circuit formed by the voltage source, conducting pads andconductive ribbon. Keeping with the above illustrative example,computing a correction at 108 comprises three computations. In thisexample, computing a correction at 108 comprises computing a resistancebased upon the known voltage and sensed current. The computed resistancemay thus include the resistance of a short section of the conductiveribbon between the spaced conducting pads. Computing a correction at 108further comprises computing a desired current for a target amount ofheat generated, e.g., a set amount of heating per square inch. Thetarget heat is correlated to a corresponding desired temperature.Computing a correction at 108 still further comprises computing anecessary voltage required to achieve the computed current based uponthe computed resistance. In this way, the current flowing through thecircuit is regulated to produce a target amount of heat that iscorrelated to the desired temperature.

For example, the desired current can be computed as the square root ofthe result of dividing a target heat generated by the computedresistance. The computed correction signal is used to alter (ifnecessary) the voltage generated and applied across the conducting padsto realize a desired temperature of the conductive ribbon. For instance,the voltage can be calculated based upon a knowledge of the newlycomputed resistance and the newly computed current. The heating per unitarea is fixed, and heat loss is a function of width and length, whichvary little in the conductive ribbon. As such, temperature isrepeatable.

Referring to FIG. 2, an exemplary system 200 is illustrated. The system200 is suited for heating a section of a conductive ribbon and isfurther suitable, for example, to implement the method 100 of FIG. 1. Inparticular, the system 200 comprises a non-conductive base 202 and asurface 204 for receiving a conductive ribbon 206. The system 200 alsocomprises a pair of conducting pads 208, each pad 208 arranged tocontact a conductive portion 209 of the conductive ribbon 206 positionedon the non-conductive base 202. For instance, in an exemplaryimplementation, the conducting pads 208 are spaced a fixed distanceapart from one another and clamp the conductive ribbon 206 to thesurface 204 of the non-conductive base 202.

A variable power supply 210 forms a circuit with the pair of conductingpads 208 and the conductive ribbon 206. Additionally, a sensor 212 ispositioned to measure at least one characteristic of the circuit as willbe described in greater detail below. A controller 214 is coupled to thevariable power supply 210 to command and/or control the signal output bythe variable power supply 210. For instance, in an exemplaryimplementation, the variable power supply 210 is implemented as avariable voltage source controlled by the controller 214. In thisregard, the controller 214 can vary the voltage output by the variablepower supply 210. Keeping with the example above, the sensor 212comprises a current sensor in-line with the circuit formed with thevariable voltage source 210, conducting pads 208 and conductive ribbon206. As illustrated, the current sensor 212 is in-line between apositive terminal of the variable power supply 210 and a conducting pad212. However, in practice, the sensor 212 may be implemented by otherconfigurations and/or circuit locations.

The controller 214 is configured to control the variable power supply210 to heat a short section 215 of the conductive ribbon 206, i.e., thesection of the conductive ribbon 206 positioned between the conductingpads 208 to a desired, controlled temperature. In an illustrativeimplementation, the controller 214 controls the variable power supply210 to apply a signal, e.g., a voltage, to the conductive ribbon 206.The controller 214 takes a measurement associated with the conductiveribbon 206 in response to the applied signal and computes a correctionfor the applied signal to achieve a desired temperature. Based upon thecomputed correction, the controller 214 controls the variable powersupply 210 to adjust the applied signal to regulate the heat of theconductive ribbon 206 to the desired temperature. The conductive ribbon206 is held at a desired, heated temperature (or temperature range) thatis suitable for processing a sample on the conductive ribbon 206, e.g.,fixing, drying, etc., for a desired amount of time.

The conductive ribbon 206 comprises any suitable conductive ribbon, suchas a thin aluminum coating on a polyester tape. As another illustrativeexample, the conductive ribbon 206 may comprise a fully metallicconductive ribbon. Thus, a low cost sample substrate is provided, whichis suitable for processing samples, which may include proteins,micro-organisms, etc.

Conductive ribbons 206 are typically very thin. As such, a small changein the thickness of the conductive ribbon 206 can have a radical changeon the resistance of the conductive ribbon and, thus, the temperature towhich each conductive ribbon will heat given a fixed signal, e.g., afixed voltage from the variable power supply 210.

However, power is a measure of energy per unit of time and is thus theequivalent of heat generated. Power (or heat loss) of a resistance isthus given by:P=I²R or I=Sqrt(P/R)

where P is the power, I is the current and R is the resistance.

Because the spacing between the conducting pads 208 is set, the lengthof the conductive ribbon 206 between the conducting pads will remainconstant. Moreover, the width of the conductive ribbon 206 does not varysignificantly. Heat loss in the conductive ribbon 206 is a function ofwidth and length, which are fixed in the system 200. As such, theability to set the temperature to a desired value or range isrepeatable, despite variances that may occur in the thickness of variousconductive ribbons, or variances that may occur in sections of the sameconductive ribbon 206.

According to aspects of the present invention, the controller 214 isprogrammed to compute a correction by computing a resistance of theconductive ribbon 206, e.g., based upon the applied voltage from thevariable power supply 210 and the measured current as measured by thesensor 212. The computation of the resistance thus accounts for thelikely variance in resistance for different conductive ribbons orsections of conductive ribbon 206 utilized in the system 200. Thecontroller 214 further computes a desired current based upon a targetheat generated and the computed resistance.

For instance, the controller 214 can compute the desired current bycomputing the square root of the result of dividing a target heatgenerated, by the computed resistance, e.g.:I∝sqrt(q′/R)

In the above formula, I is the desired current, q′ is the target heatgenerated, and R is the computed resistance.

Once the newly measured resistance (R) and the newly computed current(I) are known, the controller 214 computes the new voltage required bythe variable power supply 210 to maintain (or obtain) the desiredtemperature.

At startup, the temperature of the conductive ribbon 206 will likely beless than the target temperature. As such, the controller 214 mayutilize any number of techniques to initially heat the conductive ribbon206 so that the conductive ribbon 206 heats up over time to towards thedesired temperature. For instance, the controller 214 can adjust thevariable power supply 210 to a fixed value or set a limit to the voltageapplied by the variable power supply 210 to limit or otherwise controlthe rate at which the conductive ribbon 206 heats up over time.

Temperature can be correlated with heat generated (q′) in a number ofways. Regardless, by correlating a desired temperature with acorresponding heat generated, a target heat value is obtained. Basedupon this known target heat value, and the measured resistance, thedesired current can be computed to obtain the target heat. Since thetarget heat is correlated with a desired temperature, the conductiveribbon 206 is heated to the desired temperature.

According to aspects of the present invention, temperature is repeatablesince the system addresses energy in a fixed area and the heat loss inunaffected by the coating thickness of the conductive ribbon 206.Rather, the heat loss is affected by the width and length of theconductive ribbon 206 in the area between the conducting pads 208. Thelength of the conductive ribbon 206 between the conducting pads 208 andwidth of the conductive ribbon 206 are assumed to remain constant or areotherwise known.

Any number of approaches may be utilized to map or otherwise translatethe heat (q′) to a desired temperature. In this regard, as the current(I) increases, energy is added into the system, which translates intoheat (q′), thus affecting the temperature of the conductive ribbon 206.However, factors such as the heat dissipation of the non-conductive base202, the properties of the conductive ribbon 206, air flow in theenvironment of the system 200 and other factors will affect therelationship between the electrical energy converted to heat, and acorresponding temperature.

According to various aspects of the present invention, the controller214 utilizes calibration data 216 to translate a desired temperature toa corresponding target heat (q′). The calibration data 216 may be storedwithin the controller 214 or may be otherwise accessible to thecontroller 214. The calibration data 216 can be stored as a set of datapoints, e.g., for curve fitting, interpolation, etc. The calibrationdata 216 may alternatively be stored as a correction formula, map orother transformation. According to further aspects of the presentinvention, a calibration can be performed as necessary to map power andthus heat generated, to a corresponding temperature. For instance, arepresentative conductive ribbon can be installed in the system, andactual temperature measurements can be collected at two or more powerlevels. The power (heat generated) and temperature can be stored as datapoints, and the generated data points can be stored as the calibrationdata. Thus, the system 200 can be reconfigured to accommodate changes toconditions that affect the correlation between power and temperature.

According to aspects of the present invention, the two conducting pads208 clamp to the conductive ribbon 206 so as to form a circuit with thevariable power supply 210. The controller 214 controls the variablepower supply 210 and can read the sensor 212 so as to control the systemto heat the conductive ribbon 206 to a desired temperature.

As an illustrative example, the controller 214 causes the variable powersupply 210 to apply a low voltage to the fixed, spaced apart conductingpads 208. The conducting pads 208 clamp a small section of conductiveribbon 206 between and bridging the conducting pads 208. The low voltagecauses the conductive ribbon 206 to heat up as current is delivered tothe circuit. The controller 214 senses the current using the sensor 212,allowing the controller 214 to measure/compute the resistance associatedwith the circuit. The controller 214 also calculates a necessary currentto achieve a set amount of heating per unit area, e.g., per square inch,based upon the current measured resistance. That is, a desired currentis computed to correspond with a target heat generated. The target heatis correlated with a desired temperature. The controller 214 uses thecomputed current and computed resistance to determine a new voltagelevel. The above process is repeated as necessary to obtain and/ormaintain the temperature of the conductive pad 206 for a select amountof time (likely determined by the particular application).This enablesthe system 200 to heat a conductive ribbon 206 to a repeatable desiredtemperature because the heat loss is unaffected by the coatingthickness. Rather, the energy (heat loss) in this regard, is affected bythe width and length of the conductive ribbon 206 between the conductingpads 208, which are constant, as described in greater detail herein.

By way of illustration, various aspects of the present invention may beutilized in a sample clean-up process. For instance, a sample, collectedor otherwise deposited on the conductive ribbon 206, is fixed to theconductive ribbon 206 by optionally applying a fixing solution to thesample and by heating the conductive ribbon 206, using the system 200and/or the method 100. Thus, the sample may be heated to a known,controlled temperature, e.g., for a predetermined amount of timecorresponding to a desired time required to fix the sample, e.g.,containing protein or microorganism components, to the conductive ribbon206.

After fixing the sample to the conductive ribbon, the sample may beincubated and/or washed, then dried, e.g., by heating the conductiveribbon 206 and, thus, the sample for a predetermined heating time andtemperature. In this regard, the system 200 and/or the method 100 can beused to dry the sample by heating the sample on the conductive ribbon toa desired temperature for the predetermined heating time. The sample isthus prepared for subsequent sample analysis, which may includespectroscopy analysis such as a Raman spectroscopy, infraredspectroscopy, a fluorescence spectroscopy, mass spectroscopy, etc.

Referring to FIG. 3, a block diagram 300 of the controller 214 isdepicted in accordance with the present invention. The controller 214may be implemented by a data processing and control system 300, such asa server computer, general purpose computer, pervasive computing device,microcontroller, or other processing circuitry, which may include anycombination of hardware and/or software. For instance, the processingand control system 300 may comprise one or more processors 302 connectedto system bus 304. Also connected to system bus 304 is memory 306, whichmay include local memory, storage, random access memory (RAM), read onlymemory (ROM), hard disk storage, etc. I/O 308 is also connected to thesystem bus 304 and provides an interface to input/output connections,e.g., to control the variable power supply 210, to read the sensor 212and for any other necessary input/output. A network adapter 310 may alsobe coupled to the system bus 304, to enable the data processing systemto become coupled to other data processing systems. Also connected tothe bus may be devices such as a graphics adapter, etc.

The memory 306 includes a computer usable storage medium having computerusable program code embodied thereon. The computer usable program codemay be executed to implement any aspect of the present invention, forexample, to implement any aspect of the method 100 described withreference to FIG. 1, and/or to implement any aspect of the processing ofthe controller 214 described with reference to FIG. 2. The memory mayalso be used to store the calibration data 216 described with referenceto FIG. 2.

Various aspects of the present invention may take the form of anentirely hardware embodiment, an entirely software embodiment (includingsoftware, firmware, micro-code, etc.) or an embodiment combiningsoftware and hardware, wherein the embodiment or aspects thereof may begenerally referred to as a “circuit,” “component” or “system.”Furthermore, various aspects of the present invention may take the formof a computer program product embodied in one or more computer-readablestorage medium(s) having computer-usable program code embodied thereon.

Each block of the flowchart illustrations and/or block diagrams herein,and combinations of blocks in the flowchart illustrations and/or blockdiagrams may be implemented by system components or computer programinstructions. These computer program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, do not precludethe presence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

The description of the present invention has been presented for purposesof illustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the invention.

Having thus described the invention of the present application in detailand by reference to embodiments thereof, it will be apparent thatmodifications and variations are possible without departing from thescope of the invention defined in the appended claims.

What is claimed is:
 1. A method of heating a conductive ribbon, themethod comprising: clamping a conductive ribbon to a surface of anon-conductive base using conducting pads such that a selected sectionof the conductive ribbon is bound by the conducting pads; applying avoltage signal from a variable power supply across the conducting padsto cause the selected section of the conductive ribbon to heat up;taking a measurement of at least one electrical property associated withthe conductive ribbon in response to the voltage signal applied acrossthe conducting pads; placing a biological sample on the conductiveribbon between the conductive pads applying a voltage signal from thevariable power supply across the conducting pads to cause the selectedsection of the conductive ribbon to heat up; computing, based on themeasurement and Ohm's law, a correction for the voltage signal appliedacross the conducting pads to achieve a desired temperature of theselected section of the conductive ribbon, wherein the desiredtemperature is selected for processing the biological sample on theconductive ribbon and the correction accounts for a variance in theselected section of the conductive ribbon; adjusting the applied voltagesignal based upon the computed correction to regulate the selectedsection of the conductive ribbon at the desired temperature; and holdingthe selected section of the conductive ribbon at the desired temperaturefor a predetermined time.
 2. The method according to claim 1, whereinapplying a signal comprises applying a low voltage to the conductiveribbon through the conducting pads.
 3. The method according to claim 2,wherein taking a measurement comprises reading a current flowing throughthe selected section of the conductive ribbon.
 4. The method accordingto claim 3, wherein computing a correction comprises: computing aresistance of the selected section of the conductive ribbon based uponthe applied voltage and the measured current; and computing a desiredcurrent based upon a target heat generated and the computed resistance.5. The method according to claim 4, wherein the desired current iscomputed as the square root of the result of dividing the target heatgenerated by the computed resistance.
 6. The method according to claim4, further comprising utilizing calibration data to correlate a desiredtemperature to the target heat generated.
 7. The method according toclaim 4 further comprising fixing a distance between the pair ofconducting pads.
 8. The method according to claim 1 further comprisingcollecting the biological sample as a biological sample containingproteins to be analyzed.
 9. The method of claim 1 further comprising:clamping the conductive ribbon to the non-conductive base using theconductive pads such that a different selected section is bound betweenthe conducting pads; applying the signal across the conducting pads tocause the different selected section, which is now bound between theconducting pads, of the conductive ribbon to heat up; taking ameasurement of at least one electrical property associated with thedifferent selected section of the conductive ribbon in response to theapplied signal; computing, based on the measurement of the differentselected section of the conductive ribbon, a correction for the appliedsignal to achieve a desired temperature suitable for processing abiological sample on the conductive ribbon, wherein the desiredtemperature is based on the processing and the biological sample to beprocessed; adjusting the applied signal to regulate the heat of thedifferent selected section of the conductive ribbon to the desiredtemperature; and holding the different selected section of theconductive ribbon at the desired temperature for a predetermined time.10. The method of claim 1, wherein: adjusting the applied signal toregulate the heat of the selected section of the conductive ribboncomprises utilizing a controller to control a variable power supply toapply current to the selected section of the conductive ribbon.
 11. Themethod of claim 1, further comprising performing, in a loop, theoperations of taking a measurement, computing, based on the measurement,a correction for the applied signal to achieve a desired temperature ofthe selected section of the conductive ribbon, and adjusting the appliedsignal to regulate the heat of the selected section of the conductiveribbon to the desired temperature.
 12. The method of claim 1, whereinprocessing the biological sample on the conductive ribbon includesfixing the sample to the conductive ribbon using a fixing solution andheating the conductive ribbon to the desired temperature.
 13. The methodof claim 1, wherein processing the biological sample on the conductiveribbon includes incubating the biological sample by heating theconductive ribbon to the desired temperature.
 14. The method of claim 1,wherein processing the biological sample on the conductive ribbonincludes drying the biological sample by heating the conductive ribbonto the desired temperature.
 15. The method of claim 1, whereincomputing, based on the measurement, a correction for the appliedvoltage signal to achieve a desired temperature of the selected sectionof the conductive ribbon, comprises: computing the correction for theapplied voltage signal to achieve a desired temperature, wherein thecorrection accounts for a variance in a thickness of the section of theconductive ribbon.
 16. A method for heating a section of a ribboncomprising: providing a non-conductive base having a surface forreceiving a conductive ribbon; applying a pair of conducting pads acrossthe conductive ribbon such that each conducting pad of the pair ofconducting pads contacts a conductive portion of the conductive ribbonwhen the conductive ribbon is positioned on the surface of thenon-conductive base, defining a section of the conductive ribbon betweenthe pair of conducting pads; providing a variable power supply to form acircuit with the pair of conducting pads and the section of theconductive ribbon between the pair of conducting pads; providing asensor that measures at least one electrical characteristic of thecircuit; and providing a controller coupled to the variable powersupply, wherein the controller is operative for: controlling thevariable power supply to apply a signal to the conductive ribbon tocause the section of the conductive ribbon between the pair ofconducting pads to heat up; collecting a measurement taken using thesensor in response to the applied signal; computing a correction for theapplied signal to achieve a desired temperature selected for processinga sample on the heated section of the conductive ribbon; and adjustingthe applied signal to regulate the heat of the conductive ribbon to thedesired temperature for a time that is suitable for processing thesample on the section heated conductive ribbon.
 17. The method of claim16, wherein: controlling the variable power supply to apply a signal tothe conductive ribbon comprises controlling the variable power supply toapply a voltage signal to the conductive ribbon; and collecting ameasurement taken using the sensor comprises collecting the measurementby sensing a current in the circuit.
 18. The method of claim 17, whereincomputing a correction comprises: computing a resistance of the sectionof the conductive ribbon between the pair of conducting pads based uponthe voltage signal and measured current; computing a desired current fora target amount of heat generated, wherein the target amount of heat iscorrelated to the desired temperature; and computing a necessary voltageto achieve the computed desired current.
 19. The method of claim 18,wherein computing a desired current comprises computing the desiredcurrent as the square root of the result of dividing the target amountof heat by the computed resistance.
 20. The method of claim 18 furthercomprising: spacing the pair of conducting pads a fixed distance fromone another and clamping the conductive ribbon to the surface or thenon-conductive base; defining the heat per unit area that is fixed basedupon width and length; and using resistance to account for variation inthickness.